Ram jet engine



G. W. KALLAL Oct. 27, 1953 RAM JET ENGINE 3 Sheets-Sheet 1 Filed Feb. 19, 1949 INVENTOR. W W Maj, @aMv @44 7 HIS ATTQRNEYS Oct. 27, 1953 G. w. KALLAL 2,655,676

RAM JET ENGINE Filed Feb. 19. 1949 3 Sheets-Sheet 2 $1 w. KM, 51 MMQU/GM INVENTOR.

HIS ATTORNEYS.

Oct. 27, 1953 6. WI KALLAL 2,656,676

RAM JET ENGINE Fild Feb. 19. 1949 s Sheets-Sheet s INVENTOR'.

w. KM

HIS ATTORNEYS.

Patented Oct. 27, 1953 RAM JET ENGINE George W. Kallal, Overland, Mo., assignor to McDonnell Aircraft Corporation, St. Louis, Mo., a corporation of Maryland Application February 19, 1949, Serial No. 77,351

(Cl. GIL-35.6)

12 Claims. 1

This invention relates to ram jet engines and is more particularly directed to an improved combined arrangement of a fuel nozzle, flame holder, and diffuser construction for such engines.

The object of the invention is to provide a ram jet engine in which the combination flame holders and diffuser element are so constructed and arranged that they cooperate with the diffuser element of the engine for increasing the difiusion of fuel and air entering the engine.

Another object of the invention is to provide a ram jet engine having a diffusing chamber in the forward portion thereof in which are assembled combination flame holder and air diffusing elements on which the fuel nozzles are mounted.

A still further object of the invention is to provide fuel nozzles on the leading ridges of the combined air diffuser and flame holder for ram jet engines.

The invention consists in providing a device comprising a tubular casing having contracted forward and rearward ends constituting intake and exhaust orifices and in which a diffusing chamber is formed in the forward end of the tubular casing, in which chamber a plurality of annular concentrically disposed hollow V-sectioned members are arranged whose sides extend rearwardly into the tubular casing. The invention also consists in providing a fuel nozzle in the diffusing chamber having an orifice therein that discharges fuel toward the forward end of the casing directly into the incoming air stream providing the fuel that is burned in the central portion of the casing, and other flame holders having a plurality of nozzles arranged on the leading ridge thereof whose orifices discharge fuel toward the forward end of the casing directly into the air stream and supply the fuel that is burned outwardly from the central portion toward the inner periphery of the tubular casing.

In the drawings:

Fig. 1 is an elevational view, partly in section, of a ram jet engine,

Fig. 2 is a sectional view taken substantially along the line 2--2 of Fig. 1,

Fig. 3 is a front elevational view of the ram jet engine,

Fig. 4 is a longitudinal sectional view of a portion of the afterburner incorporating the casing; and

Fig. 5 is a sectional view taken substantially along the line 5--5 of Fig. 4.

The ram jet engine is embodied in a tubular casing I having its ends contracted to form the exhaust and intake orifices therefor. A suitable bracket 2 is secured to the casing whereby the engine may be mounted on the outboard end of a helicopter rotor blade, or to any other movable body. .An annular ring 3 is provided in the forward end of the casing and the material of the shell for forming casing l is partially curled about and secured to the ring. The forward end of the casing is provided with a liner ll one end of which is curled about and secured to the annular ring 3, its opposite end being led rearwardly into the casing and secured to the wall thereof to define a diffusing chamber in the forward end of the casing.

A plurality of annular concentrically arranged hollow substantially V-shaped section flame holders 5 and 6 are mounted in the diffusing chamber by means of a plurality of struts I having a hollow V-shaped section similar to that of the flame holders. The ridges of flame holders 5 and B and the struts l are rounded so that the resistance to air movements may be better controlled. The radius of the ridge of flame holder 5 is formed to a comparatively short dimension and the ridge of flame holder 6 is formed to a somewhat larger radius, making the ridge of flame holder 5 comparatively sharp and that of flame holder 6 blunt. The outermost side of flame holder 5 is formed so that its surface is substantially parallel to the surface of liner 4. The angle of the other side of flame holder 5 with the longitudinal axis of casing I, and the angle of each of the sides of flame holder 6, gradually decreases so that the inner surface of flame holder 6 is substantially parallel to the longitudinal axis of casing I. The sides of the flame holders, especially those of 6, constitute, in effect, an inner wall of the diffusing chamber. The fuel system for the ram jet engine consists of a forked memher 8 provided with a conduit 9 that lies along the longitudinal axis of the casing and has a nozzle l0 mounted thereon pointing forwardly whose orifice discharges fuel directly into the incoming air stream. The nozzle is positioned just aft of the annular ring 3 so that the fuel discharged from the nozzle will not be carried too far forwardly into the air stream. The member 8 has a plurality of conduits ll secured thereto that lead to and are positioned within flame holder 5. Each conduit terminates in the ridge thereof for enabling nozzles 12 to be secured to each of the conduits, thereby positioning the nozzles l2 radially outwardly from nozzle 10. The orifice in each of the nozzles I2 is preferably smaller than the orifice in nozzle l0 and discharges fuel into the incoming air stream. The

:nozzles 12 are substantially aligned in the same plane with nozzle l0 and supply the fuel that is burned outwardly from the central portion of the casing toward the inner peripheral surface thereof. Nozzle I!) supplies the fuel that is burned in the central part of easing l. Fuel is supplied. to the forked member 8 by conduit I3 that extends rearwardly into the casing and then passes through the wall thereof for connection to a suitable source of supply.

The initial ignition of fuel is accomplished by means of a spark plug I4 connected to a suitable ignition coil (not shown). Once the fuel has been ignited, the burning process is continuous, thus enabling disconnection 'of the spark coil from plug I I.

After moving the engine casing through the air at a given speed, it is supplied with fuel through nozzle Ill and nozzles I2 after which it is ignited by spark plug Hi. The nozzle Ill having a large orifice therein, discharges its fuel and, by reason of the rapidly moving air entering the casing; it will flow back upon itself into the combustion chamber of the engine. In order to secure better distribution of fuel and air in the combustion chamber, flame holder 5 has been provided with sides that extend'into the casing I to a point where the wall thereof begins to be substantially parallel to the longitudinal axis thereof. The comparatively blunt ridge on flame holder 6 in combination with the long sides of the flame holder, increases the diffusion of fuel and air so that when it reaches the combustion chamber the burning of the fuel will be more complete and the holding qualities of flame holder 5 will be correspondingly increased. The fuel nozzles I2 are aligned with flame holder 5 and preferably disposed at an angle to the longitudinal axis of thecasing and discharge fuel directly into the incoming air stream. This fuel is likewise carried back on itself toward the combustion chamber and, by reason of the increased angle of the slope of the sidesofflame holder 5 with respect to the longitudinal axis of the casing and the sharper ridge thereon, assists in guiding the flow as well as aiding in difiusing the. fuel and air'stream passing'between flame holders 5 and 6 and the.

diffusing chamber liner 4. Theflame holder 5 directs the diffused fuel and. air stream so that considerable combustion will occur adiacent' the inner periphery of the casing where its burning will produce an optimum output. The configuration of each of the flame holders 5 and 6 and of the liner I by increasing the diffusion of air and fuel, will cause the flame holders to hold the flame and secure a more complete combustion thereof; The flame holders also enable the over-all length of thecasing I to be shortened, thus assuring that fuel combustion will occur Within casing I.

a Figs. 4 and 5 illustrate the application of the combination flame holder and diffusing elements described in connection with Figs. 1 to 3, to an afterburner securable to the exhaust end of a turbo jet engine.

The improved flame holder and diifuser construction is assembled in casing I5 of an afterburner, only a. portion of which being shown. The casing I5 is provided with a flange 56 at one end thereof which is secured to a complemental flange I! mounted on the turbo jet engine. Concentrically arranged annular hollow substantially V-shaped section flame holders I8 and I9 are mounted in casing I5 by means of suitable supports 20.- A diffuser cone 2! is mounted centrally of casing I5 and in combination therewith forms the diifusing chamber in which the flame holders I8 and I9 are mounted. The flame holders extend from the point adjacent the left hand end of casing I5, as viewed in Fig. 4, and are preferably, though not necessarily, coextensive in length with the diffuser cone 2 I.

Fuel nozzles 22 are mounted on the rounded forward ends of flame holders I8 and I9 and are.

so disposed thereon that the discharge orifices in the nozzles will supply sufficient fuel for the afterburner. Each of the nozzles has a conduit 23 leading thereto positioned within the flame holders I8 and I9 and are connected to a conduit 24 leading to a suitable source of fuel supply. The initial ignition of fuel is accomplished by means of spark plug 25 mounted in casing I5 that is connected to a suitable spark coil. The afterburner is mounted on the exhaust end of the turbo jet engine and when it is desired to increase the thrust output thereof, fuel is supplied to nozzles 22 which discharge'fuel into the exhaust air stream derived from the turbo jet engine. This fuel will flow back upon itself to casing I5 and since the sides of the flame holder IS are substantially parallel to the sides of easing I5, and since the sides of flame holder I8 are substantially parallel to the surface of the diffuser cone 2 I, the diffusion of fuel and air will be greatly increased to secure a more complete combustion of fuel and for better enabling the flame holders I8 and I9 to hold the flame in the combustion chamber of the afterburner. The operation of this device is the same as that described in connection with the ram jet engine embodiment of the invention.

What I claim is:

l. A ram jet engine comprising a tubular casing having contracted open rearward and forward ends; a plurality of annular concentrically arranged substantially V-shaped section flame holders the V edge of each facing forwardly and having longitudinally extended sides and mounted in the forward end of said casing, the outer flame holder having one of its sides substantially parallel to the wall of the casing and the inner flame holder having its sides substantially parallel to the longitudinal axis of said casing; and means arranged in the central forward end of said casing for introducing fuel into the casing and projecting it forwardly against the incoming air stream.

2; A ram jet engine comprising a tubular casing having forward and rearward ends; a plurality of annular concentrically arranged substantially V-shaped section flame holder mem bers having longitudinally extended sides, in the forward end of said casing whose ridges face forwardly; means for supporting said J members in said casing, the outer flame holder having one of its sides substantially parallel to the wallet" the casing and the inner flame holder having its sides substantially parallel to the longitudinal axis of said casing; and means for introducing fuel into said casing forwardly of the ridges of said flame holders and projecting it forwardly against the incoming air stream.

3. A ram jet engine comprising a tubular casing having contracted'op'en rearward and forward ends a plurality of annular concentrically arranged substantially Veshaped section flame holders mounted in the forward end of said casing, the ridge of each facing forwardly; means arranged in the central forward end of said cas- 'ing for introducing fuel into said casing and projecting it forwardly against the incoming air stream; and other means secured to the ridge of one of said flame holders for introducing fuel into said casing and projecting it forwardly against the incomin air stream.

4. A ram jet engine comprising a tubular casing having contracted forward and rearward ends; a plurality of annular concentrically arranged substantially v-shaped flame holders mounted in the forward end of said casing, the sides of said V flame holders being longitudinally extended and whose V edges face forwardly; a liner assembled in the forward end of said casin for forming one wall of a diffusing chamber, the outer flame holder having one of its sides substantially parallel to the liner and one of the sides of the inner flame holder being substantially parallel to the longitudinal axis of said'tubular casing, the other sides of each of the flame holders diverging from the first mentioned sides thereof; and means for introducing fuel into said casing forwardly of said ridges and projecting it forwardly against the incoming air stream.

5. A ram jet engine comprising a tubular casing having contracted rearward and forward ends; a liner forming a diffusing chamber arranged in the forward end of said casing; a plurality of annular concentrically arranged substantially V-shaped section flame holders disposed within the diffusing chamber whose ridges face forwardly and which extend rearwardly into said casing; means disposed in the central forward part of the casing ahead of the ridges for introducing fuel into said casing and projecting it forwardly against the incoming air stream; and other means secured to the ridge of one of said flame holders for introducing fuel into said casing and projecting it forwardly against the incoming air stream.

6. A ram jet engine comprising a tubular casing open at its rearward and forward ends; a liner arranged in the forward end of said casing for forming a diffusing chamber therein; a plurality of annular concentrically disposed substantially V-shaped section flame holders arranged in said chamber whose ridges face forwardly and whose sides extend rearwardly into said casing, one side of the outermost flame holder bein substantially parallel with the surface of said liner and the other side of said outermost flame holder diverging therefrom, one side of the innermost flame holder diverging from the other side of said outermost flame holder, the other side of said innermost flame holder being substantially parallel to the longitudinal axis of said casing; and means for introducing fuel forwardly of the ridges of said V members and projecting it forwardly against the incoming air stream.

'7. A ram jet engine comprising a tubular casing open at its rearward and forward ends; a liner arranged in the forward end of said casing for forming a diffusing chamber therein; a plurality of annular concentrically disposed substantially V-shaped section flame holders arranged in said chamber whose ridges face forwardly and whose sides extend rearwardly into said casing, one side of the outermost flame holder being substantially parallel with the surface of said liner and the other side of said outermost flame holder diverging therefrom, one side of the innermost flame holder diverging from the other side of said outermost flame holder, the other side of said innermost flame holder being substantially parallel to the longitudinal axis of said casing; a fuel nozzle for introducing fuel into the central part of said casing and projecting it forwardly against the incoming air stream; and

a plurality of fuel nozzles mounted on the ridge of one of said flame holders forward of said ridge for supplying fuel outwardly from the central portion of said casing toward the inner periphery thereof and projecting it forwardly against the incoming air stream.

8. A ram jet engine comprising a tubular casing open at its rearward and forward ends; a linerarranged in the forward end of said casing for forming a diffusing chamber therein; a plurality of annular concentrically disposed substantially V-sh-aped section flame holders arranged in said chamber whose ridges face forwardly and whose sides extend rearwardly into said casing, one side of the outermost flame holder being substantially parallel with the surface of said liner and the other side of said outermost flame holder diverging therefrom, one side of the innermost flame holder diverging from the other side of said outward flame holder, the other side of said innermost flame holder being substantially parallel to the longitudinal axis of said casing; a fuel nozzle having a discharge orifice that discharges fuel toward the forward end of said casing for burning in the central portion of the casing and projecting it forwardly against the incoming air stream; and a plurality of fuel nozzles mounted on the ridges of said flame holders, each having orifices that discharge fuel toward the forward end of said casing for burning adjacent the inner periphery of said casing and projecting it forwardly against the incoming air stream.

9. A jet type thrust producer comprising a tubular casing having open rearward and forward ends; a plurality of annular concentrically arranged substantially V-sh-aped section flame holders having longitudinally extended sides and mounted in the forward end of said casing, the ridges of each V facing forwardly the outer flame holder having one of its sides substantially parallel to the wall of the casing and the inner flame holder having its sides substantially parallel to the longitudinal axis of said casing; and means arranged in the forward end of said casing forwardly of the flame holder for introducing fuel into the casing and projecting it forwardly against the incoming air stream.

10. A jet type thrust producer comprising a tubular casing having open rearward and forward ends; a plurality of annular concentrically arranged substantially V-shaped section flame holders having longitudinally extended sides and mounted in the forward end of said casing, the ridge of each V facing forwardly, the outer flame holder having one of its sides substantially parallel to the wall of the casing and the inner flame holder having its sides substantially parallel to the longitudinal axis of said casing; and means arranged in the ridges of one of said flame holders for introducin fuel into said casing forwardly of the flame holders.

11. A jet type thrust producer comprising a tubular casing having forward and rearward ends; a plurality of annular concentrically arranged substantially v -shaped section flame holder members having longitudinally extended sides disposed in the forward end of said casing whose ridges face forwardly, the outer flame holder having one of its sides substantially parallel to the wall of the casing and the inner flame holder having its sides substantially parallel to the longitudinal axis of said casing; means for supporting said V members in said casing; and means for introducing fuel into said casing forwardly of the ridges of said flame holders and projecting it forwardly against the incoming air stream.

12. A jet type thrust, producer comprising a tubular casing having tapered and contracted forward and rearward ends said tapered forward end forming one side of a diffusing chamber; a plurality of annular concentrically arranged substantially t -shaped section members mounted in. the forward end of said casing, one side of the outermost fiaine holder being substantially parallel with the tapered forward end of said casing and the other side of said flame holder diverging therefrom and being substantially parallel with the longitudinal axis of said casing, one side of said innermost flame holder diverging from the other side of said outermost flame holder, other side thereof converging toward the longitudinal axis of said casing; a diffuser element mounted in said casing forming the other wall of said diffusing chamber and concentrically arranged with respect to said'flame holders; and means for introducing fuel into said casing forwardly of said ridges and projecting it forwardly against the incoming air stream.

GEORGE W. KALLAL.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,385,833 Nahigyan Oct. 2, 1945 2,482,505 Pierce Sept. 20, 1949 2,520,967 Schmitt Sept. 5, 1950 2,566,319 Deacon Sept. 4, 1951 2,566,373 Bedding Sept. 4, 1951 FOREIGN PATENTS Number Country Date 920,387 France June 4, 1947 OTHER REFERENCES Aviation magazine, March 1946 pages 60-62. 

